Dental crown remover



y 10, 1932- o. A. FLAGSTAD ET AL 1,353,080

DENTAL CROWN REMOVER Filed April 28, 1950 INVENTOR OscAR 4. FLA GSTAD BY Hu BEN 6. LEE

ATTORNEY Patented May 10, 1932 UNITED STATES PATENT OFFICE OSCAR A. FLAGSTAD, or MINNEAPOLIS, AND EUEBEN G. LEE, or norrnrnn'f r MINNESOTA DENTAL ctaowN EEMov R Application filed April 28,

This invention relates to devices for removing crowns from teeth, and the principal object is to provide means for removing such 7 crowns without the necessity for cutting them or otherwise destroying their usefulness, should it be desired to replace them as is often the case when'it is necessary to treat the tooth after the crown has been in place 7 for some time. A further object is to provide a device that is effective and practical in every way, yet simple in construction and economical to manufacture. These and other objects will be more fully pointed out in the following specification, reference being had to the accompanying drawings, in

which:

Fig. 1 is an enlarged side elevation of a preferred form of the device.

Fig. 2 is a sectional view on the line 22 a in Fig. 1.

Fig. 3 is a sectional elevation on the line 3-3 in Fig. 1.

Fig. 4 is a side elevation of a modified form of the device.

Fig. 5 is a top or plan view of a further modified form of the device.

Fig. 6 is a sectional elevation on the irregular line 66 in Fig. 5.

Referring to the drawings more particu- V a) larly and by reference characters, the device 1 shown in Figs. 1, 2, and 3 may first be described as follows: A and B designate a pair of jaws or claws, the lower ends of which are so formed that they may grip the crown to I e5 be removed, or may be engaged under the lower edge of the crown, if so desired. The upper ends of the jaws are pivoted, as at G, in the outer bifurcated ends of a cross bar D. A forked bar or yoke E is pivoted, as at A and B together in a clamp action upon the crown. The cross bar D is provided, with a forcing screw I, having a pin J at its lower end, which extends into a hole, that has previously been drilled in the face of the crown,

'56 to engage against the top of the tooth. It

1930. Serial No. 447,797.

will thus be seen thatafter the crown has first been drilled to provide av hole for the pin J, the jaws A and B are clamped upon the crown and as the screw I is forced down upon the tooth the crown will be freed from the cement by which it is securedto the tooth. In order that the device may be more conveniently manipulated or held in place by the dentist it may be provided with a handle K.

In the modification shown in Fig. 4, a pair of jaws A1 and B1 are pivoted, as at C1, to a connecting link D1, which accommodates a forcing screw I1 in the same manner as the link D retains the screw I in Figs. 1, 2, and 5 8. In this device the jaws are forced against the crown by a screw L that spreads the jaw portions above the fulcrums C1. This screw L threads in a lug M that is free to rock on the member B1, whilefthe other end of the screw-engages the member A1, as at 1-12.

The structure thus far described is similar to devices illustrated and described in our copending application, Ser. No. 225,298, filed October 10, 1929, for dental crown remover, which application matured into Patent No. 1,756,245, and to that extent the present application constitutes acontinuation in part'of application, Ser. No. 225,298.-

In the device shown in Figs. 5 and 6, jaws 30 7 and 8 are pivotally secured, as at 9 and 10 respectively, in a body member 11 which is substantially cylindrical except for a pair of oppositely disposed concave recesses 12 which serve'as'finger grips for the operator. 95 A forcing screw 13 is threaded'in the block or bodymember 11, and has a pin 14a at its lower end for engagement with the tooth from which the crown is to be removed. The upper ends of thejaws 7 and 8 are provided with set screws or adjusting screws 14 and 15, which are threaded to screw in the jaws and bear with their inner endsagainst the block 11 within the recessesin which the jaws are mounted. It will be noted 'that'the jaws 7 and 8 operate in planes which are angu- "larly disposed with respect to each other, and that the forcing screw 13 is s'lightlyoifset with respect to the clamping jaws in contradistinction from the structures shown in the other views. The purpose of this construction is to provide a device that is particularly adpatable for use in removing crowns of the so-called three quarter type, which are frequently used on front teeth where it is not necessary or desirable to cover the entire front-face of the tooth with the crown. In such cases the crown extends substantially about three quarters of the tooth, and hence derives its name by virtue of that reason.

In applying the device to a crown of that nature the hole for the pin 14a is drilled into the crown in the usual way, and after the pin 14a has been inserted thejaws 7 and 8 are clamped over the portion of the crown that extends slightly forwardly between the teeth, whereupon pressure is applied to the pin 14a by turning the forcing screw 13 to dislodge the crown from the tooth. It will be understood that a remover having its clamping jaws diametrically opposed, as in Figs. 14 inclusive, cannot be applied to a three quarter crown, as the crown covers only the back face of the tooth, and of course it is impossible to operate the securing jaws between the crown and the adjacent teeth.

It is understood that suitable modifications may be made in the structure as disclosed,

their inner ends to effect a claming action to the jaws.

5. A crown remover comprising a body block having a pair of slots angularly disposed with respect to each other, a pair of jaws pivoted in said slots, screws threaded in the respective aws for adjusting engagement with the body member, and a tooth engaging gevice adjustably carried by the body memer. I

6. A crown remover comprising a body block having a pair of slots angularly disposed with respect to each other, a pair of jaws pivoted in said slots, screws threaded in the respective jaws for adjusting engagement with the body member, and a-tooth engaging screw threaded in the body member and having a pin at one end for engagement against a tooth within the crown to be re-. moved.

Signed at Minneapolis, ,Minnesota, this 23rd day of April, 1930.

V OSCAR A. FLAGSTAD.

Signed at Hoffman, Minnesota, this 24th day of April, 1980.

REUBEN G. LEE.

provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described our invention what we claim to be new and desire to protect by Letters Patent is:

1. A crown remover comprising a body member, not more than two coacting jaws pivotally secured to the body member for movements in planes disposed angularly with respect to each other, a forcing member carried by the body member, and means for effecting a clamping action to the jaws.

2. A crown, removercomprising a body member, not more than two coacting j aws pivotally secured to the body member for movements in planes disposed angularly with respect to each other, a forcing member carried by the body member, and a pair of adjusting A screws carried by the respective jaws for effecting a clamping action thereto.

3. A crown remover comprising a body member, not more than two coacting jaws pivotally secured to the body member for movements in planes disposed angularly with respect to each other, a forcing member carried by the body member, and a pair of adjusting screws for respectively actuating the jaws.

4. A crown remover comprising a body member, not more than two coacting jaws pivotally secured to the body member for movements in planes disposed angularly with respect to each other, a forcing member carried by the body member, and a pair of adjusting screws carried by the respective jaws and respectively abutting the body member at 

